The effect of fire on seed germination of campo rupestre species in the South American Cerrado

Plant Ecology - Fire is an important disturbance in terrestrial ecosystems and plays a key role in the germination process and seedling establishment of many species. In grassland ecosystems, seeds...     

Rad9, Rad17, TopBP1 and Claspin Play Essential Roles in Heat-Induced Activation of ATR Kinase and Heat Tolerance

Hyperthermia is widely used to treat patients with cancer, especially in combination with other treatments such as radiation therapy. Heat treatment per se activates DNA damage responses mediated by the ATR-Chk1 and ATM-Chk2 pathways but it is not fully understood how these DNA damage responses are activated and affect heat tolerance. By performing a genetic analysis of human HeLa cells and chicken B lymphoma DT40 cells, we found that heat-induced Chk1 Ser345 phosphorylation by ATR was largely dependent on Rad9, Rad17, TopBP1 and Claspin. Activation of the ATR-Chk1 pathway by heat, however, was not associated with FancD2 monoubiquitination or RPA32 phosphorylation, which are known as downstream events of ATR kinase activation when replication forks are stalled. Downregulation of ATR, Rad9, Rad17, TopBP1 or Claspin drastically reduced clonogenic cell viability upon hyperthermia, while gene knockout or inhibition of ATM kinase reduced clonogenic viability only modestly. Suppression of the ATR-Chk1 pathway activation enhanced heat-induced phosphorylation of Chk2 Thr68 and simultaneous inhibition of ATR and ATM kinases rendered severe heat cytotoxicity. These data indicate that essential factors for activation of the ATR-Chk1 pathway at stalled replication forks are also required for heat-induced activation of ATR kinase, which predominantly contributes to heat tolerance in a non-overlapping manner with ATM kinase.     

Bacteriophages of l-Glutamic Acid-Producing Bacteria

The growth characteristics of phages were investigated with the four phages, active on Brevibacterium lactofermentum, which were selected from the respective serological groups, namely, P465 (group I), P468II (group II), Ap85III (group III) and P4 (group IV).

The adsorption rate of the phages, P465 and P468II, on the host bacteria was low, whereas that of the phages, Ap85III and P4, was higher. The adsorption rate constants for the four phages were respectively calculated at 2.02 × 10^?10, 1.87 × 10^?10, 4.32 × 10^?10 and 3.15 × 10^?10 cm³ per minute, at 30°C in G₅B₂ medium. With reference to the ionic environment for adsorption, the phages, P465 and Ap85III, specifically required either for Ca⁺⁺ or Mg⁺⁺; the phage P468II, for both; and the phage P4, for neither.

The growth characteristics of these phages were examined by the one-step growth experiment. The latent periods of the phages were 50, 53, 57 and 47 minutes, respectively; and the corresponding average burst sizes were about 98, 31, 145 and 126. The growth of the phage P4 was completely suppressed at above 34°C, although the host bacteria and the other three phages were capable of the full growth at that temperature.     

Single-laboratory validation for the determination of caffeic acid and seven caffeoylquinic acids in sweet potato leaves

A single-laboratory validation study was conducted on an HPLC method for the detection and quantification of caffeic acid (CA) and seven species of caffeoylquinic acids (CQAs) in lyophilized sweet potato leaves. The procedure for extraction of the analytes from the matrix and the HPLC conditions for the efficient separation of CA and CQAs were optimized. In the proposed method, a relative response factor to one of the CQAs (5-CQA) was used to quantify the others. The method performed well in terms of precision when carried out on five different days and demonstrated Horwitz ratio (HorRat) scores ranging from 0.5 to 1.0 for all analytes, which were well within the limits of performance acceptability. Accuracy testing at three levels showed an overall recovery of 94% when duplicated on five different days. Moreover, a stability study revealed that all analytes in both standard solution and sample extract were stable for 28?days.     

Bacteriophages of l-Glutamic Acid-Producing Bacteria

Some of the characteristics of the four phages, P 465 (group I), P 468 II (group II), Ap 85 III (group III) and P 4 (group IV), of Brevibacterium lacto fermentum, i.e., stability in salt solution, thermal and pH stabilities, inactivation by ultraviolet irradiation, stability on air-drying, and lytic characteristics of infected cells, are descrided. We have observed differences in these physico-chemical characteristics among these four phages selected from the respective serological groups. An addition of protein such as casein to diluent at a 0.01 ~ 1% concentration increased remarkably the stabilities on shaking of these phages except Ap 85 III. There were great differences in stabilities on air-drying among the four phages. Phage P 61 (gropu I) which was isolated from the first abnormal fermentation broth showed the lowest stability in the dry state, while phages, P 468 II and Ap 85 III, were very stable and were not inactivated by the relative humidity of 10% at 30°C, for the period of five months. In general, Ар-series phages isolated from air-borne particles at fermentation factory can be distinguished from the other P-series phages which were isolated from abnormal fermentation broth, by their considerably high resistance to drying.     

Gas Chromatographic Determination of a New Fungicide,Procymidone (Sumilex®) in Technical Preparation and Formulation

Monoclonal antibodies (MoAbs) reacting with human G-CSF and /or its muteins were established by cell fusion between P3.X63/Ag8.U1 myeloma cells and spleen cells from BALB/C mice immunized with recombinant human intact G-CSF or its mutein, designated ND28. Two MoAbs reacted with intact G-CSF and all kinds of muteins tested, designated KM341 and KM342, and two MoAbs specific for intact G-CSF, designated KM340 and KM343, were obtained from the mice immunized with recombinant human intact G-CSF.

The sera from the mice immunized with a mutein of G-CSF, ND28, reacted with intact G-CSF and all muteins tested. Two MoAbs specific for ND28, designated KM498 and KM511, were obtained from these mice. These MoAbs seem to recognize the sequence of a few amino acids that is peculiar for ND28. However, the epitopes recognized by KM498 and KM511 were maybe subtly different, because KM498 and KM511 could not completely inhibit each other.

Human G-CSF and/or its muteins could be measured by sandwich ELISA using these MoAbs with suitable combinations. The immuno-affinity column using KM342 or KM498 adsorbed G-CSFs or specifically ND28, previously. By elution with 0.15m NH₄OH, the G-CSFs or ND28 were eluted with a high recovery.     

Association study and expression analysis of porcine ESR1 as a candidate gene for boar fertility and sperm quality

Male fertility is impaired through the lack of ESR1 (Estrogen Receptor 1) but little is known about the ESR1 roles in boar spermatogenesis and fertility. Therefore, this research was aimed at investigating the association with sperm quality and boar fertility traits in a total of 300 boars both from purebred Pietrain and Pietrain × Hampshire crosses. A SNP in coding region of ESR1g.672C>T in exon 1 was associated with sperm motility (P<0.05) and plasma droplet rate (P<0.01) while the polymorphism in non-coding region of ESR1g.35756T>C in inton 1 was associated with non-return rate (P<0.05). Furthermore, to analyse the mRNA and protein expression of ESR1 in boar reproductive tissues, a total of six boars were divided into two groups [Group I (G-I) and Group II (G-II)], where G-I had relatively better sperm quality. ESR1 expression was higher in tissues collected from G-I boars than those of collected from G-II boars, and the difference in mRNA expression was significant (P<0.01) in head of epididymis. The ESR1 protein expression results from western blot coincided with the results of qRT-PCR. The ESR1 protein localization observed a strong staining in the cytoplasm of Sertoli cell in the testis, in the epithelial cells in head and tail of epididymis, in smooth muscle in tail of epididymis, and in the post acrosomal region and tail of the spermatozoa. These results will improve the understanding of the functions of the ESR1 in spermatogenesis within the reproductive tract and will shed light on ESR1 as a candidate in the selection of boar with good sperm quality and fertility.     

The effects of an arabinogalactan-protein from the white-skinned sweet potato (Ipomoea batatas L.) on blood glucose in spontaneous diabetic mice

We examined the effects of an arabinogalactanprotein (WSSP-AGP) from Ipomoea batatas L. on hyperglycemia in db/db mice. An oral glucose tolerance test indicated significantly decreased plasma glucose levels by WSSP-AGP. Additionally, an insulin tolerance test found improvement in insulin sensitivity due to treatment with WSSP-AGP. This suggests that amelioration of insulin resistance by WSSP-AGP causes to lead its hypoglycemic effects.